A colour indicator film based on bromothymol blue/poly‐L‐lactic acid/polyvinylpyrrolidone for detecting bacteria

Abstract

The unintentional bacterial contamination in food seriously harms food quality and human health, so it is necessary to establish a real‐time bacterial detection method. Here, a colour indicator film was designed to detect bacterial by incorporating bromothymol blue (BTB) into degradable poly‐L‐lactic acid (PLLA) and polyvinylpyrrolidone (PVP). The colour indicator film was prepared into fibres by electrospinning technology. The colour indicator film showed colour responsiveness from yellow to green at different pH. The colour indicator film showed good colour stability at different temperature and humidity conditions. The colour indicator film was used for the detection of bacteria, and it was found that the colour indicator film could make a colour response visible to the naked eye according to different concentrations of bacteria, which showed the great potential of the colour indicator film in detecting bacteria.

Color changing bioadhesive barrier for peripherally inserted central catheters

“…Several known microorganism indicators are screened including resazurin, 33 nitrazine yellow, 34 bromocresol purple, 34 bromocresol green, 35 thymol blue 36 and bromothymol blue. 30 The following criteria narrows the selection: (i) the indicator response needs to be rapid (<10 min) for infection prevention; 28 (ii) colorimetric change should not be confused with the color of blood; (iii) disperse in the liquid polymer matrix; (iv) retain gelation properties; and (v) commericial availability. Bromothymol blue (BTB) meets all of the above criteria (data not shown).…”

“…Bromothymol blue (BTB) is a known candidate for bacterial detection. 30–32 (2) Photocured CathoGlu reduces bacteria permeability by one order of magnitude or more. Finally, a non-inferiority pre-clinical in vivo study (porcine model) compares CathoGlu to clinically approved adhesive formulation and tape.…”

A Color Indicator Based on 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT) and a Biodegradable Poly(ester amide) for Detecting Bacterial Contamination

“…These pathogens can cause food-borne diseases ( B. cereus , S. aureus ), as well as sometimes gastroenteritis ( E. coli , S. enterica ) and systemic disease ( E. coli O157:H7, L. monocytogenes ) [ 8 , 9 ]. Some methods commonly used to detect bacterial contamination in food are those based on polymerase chain reaction (PCR) [ 10 ], fluorescence, in situ hybridization flow cytometry, oligonucleotide DNA microarray [ 11 ], optical biosensors [ 12 ], amperometric electrode systems [ 13 ], mass-based biosensors [ 14 ], or color indicator film based on pH changes [ 15 ].…”

“…Generally, direct incorporation is the method used to functionalize nanofibers by adding substances, such as nanoparticles, organic compounds, dyes, nanomaterials, and biomolecules, to the polymer solution before electrospinning [ 16 , 19 ]. Recently, Sun et al designed a color indicator film to detect bacteria in food by incorporating bromothymol blue (BTB) into degradable poly-L-lactic acid (PLLA) and polyvinylpyrrolidone (PVP) using the electrospinning technique [ 15 ].…”